The present disclosure relates generally to methods and apparatuses for detecting and identifying chemicals in aerosol-particles and/or on surfaces. More particularly, the present invention relates to a hand-held laser based biosensor using “label-free” or native molecular fluorescence spectrophotometry for direct sampling of native biomolecules in solids, fluid, and/or atmospheric air.
While portable spectrophotometers are known to operate effectively on liquid samples, these devices encounter challenges when operating directly on atmospheric air or solids. Further, while laser molecular spectrophotometry has shown some success in remote sensing of atmospheric air or solids, challenges remain about safety concerns when laser beams are exposed to atmosphere, the useable wavelength of the lasers, and the lack of detection sensitivity.
As such, there remains a need for a portable biosensor for direct sampling on solids and/or atmospheric air, including particles, aerosols and spores, by using laser-based molecular fluorescence spectrophotometry.
According to an illustrative embodiment of the present disclosure, a hand-held biosensor includes an electromagnetic radiation emitter configured to emit a laser beam in a first direction along a first longitudinal axis, the laser beam having a wavelength of between 260 nm and 290 nm, which is used for excitation of amino acids tryptophan and tyrosine that are present in biomolecules. The hand-held biosensor further includes a first band pass filter configured to reflect the laser beam in a second direction along a second longitudinal axis substantially perpendicular to the first longitudinal axis toward a target, the first band pass filter configured to permit passage therethrough of fluorescence emissions from the target in a third direction along the second longitudinal axis opposite the second direction. A photo-detector is configured to receive the fluorescence emissions, and a processor is in electrical communication with the photo-detector to receive fluorescence spectral data from the photo-detector. A signal display is in electrical communication with the processor and is configured to provide an indication of the fluorescence spectral data. A first power supply is an electrical communication with the electromagnetic radiation emitter.
According to another illustrative embodiment of the present disclosure, a hand-held biosensor includes a housing having a lower handgrip portion extending between a lower end and an upper end along a first longitudinal axis, and an upper target portion extending between proximal end and a distal end along a second longitudinal axis substantially perpendicular to the first longitudinal axis. An electromagnetic radiation emitter is received within the lower handgrip portion and is configured to emit a laser beam in a first direction along the first longitudinal axis, the laser beam having a wavelength of between 260 nm and 290 nm, which is used for excitation of amino acids tryptophan and tyrosine that are present in biomolecules of a target. A first band pass filter is configured to reflect the excitation laser beam in a second direction along the second longitudinal axis substantially perpendicular to the first longitudinal axis toward the target, the first band pass filter configured to permit passage therethrough of fluorescence emissions from the target in a third direction along the second longitudinal axis opposite the second direction. A photo-detector is received within the upper target portion of the housing and is configured to receive the fluorescence emissions. A processor is in electrical communication with the photo-detector and is configured to receive fluorescence spectral data from the photo-detector. A signal display is in electrical communication with the processor and is configured to provide an indication of the fluorescence spectral data. A first power supply is in electrical communication with the electromagnetic radiation emitter. An adapter is releasably coupled to the distal end of the upper target portion of the housing for collecting ambient air.
According to a further illustrative embodiment of the present disclosure, a hand-held biosensor includes a housing having a lower handgrip portion extending between a lower end and an upper end along a first longitudinal axis, and an upper target portion extending between a proximal end and distal end along a second longitudinal axis substantially perpendicular to the first longitudinal axis. An electromagnetic radiation emitter is received within the lower handgrip portion and is configured to emit a laser beam in a first direction along the first longitudinal axis, the laser beam having a wavelength of between 260 nm and 290 nm. A first band pass filter is configured to reflect the laser beam in a second direction along the second longitudinal axis substantially perpendicular to the first longitudinal axis toward a target, the first band pass filter configured to permit passage therethrough of fluorescence emissions from the target in a third direction along the second longitudinal axis opposite the second direction. A photo-detector is received within the upper target portion of the housing adjacent the proximal end and is configured to receive the fluorescence emissions. A second band pass filter is supported adjacent to the distal end of the upper target portion, the second band pass filter covering the spectral region of between approximately 250 nm and approximately 400 nm. At least one lens is received within the target portion of the housing and defines a focal length for the laser beam to engage the target, the target portion of the housing including a first portion telescopingly coupled to a second portion for moving the at least one lens and thereby adjusting the focal length. A processor is in electrical communication with the photo-detector to receive fluorescence spectral data from the photo-detector. A signal display is in electrical communication with the processor and is configured to provide an indication of the fluorescence spectral data. A first power supply is in electrical communication with the electromagnetic radiation emitter, and a second power supply is in electrical communication with the signal display. The second power supply includes a battery supported by the target portion of the housing, and the signal display includes a liquid crystal display supported by the target portion of the housing. An adapter is releasably coupled to the distal end of the upper target portion of the housing for collecting ambient air.
Additional features and advantages of the present invention will become apparent to those skilled in the art upon consideration of the following detailed description of the illustrative embodiments exemplifying the best modes of carrying out the invention as presently perceived.